Te Awarua-o-Porirua Whaitua PART 1 Presentation to Te - - PowerPoint PPT Presentation

Managing sediment in Te Awarua-o-Porirua Whaitua PART 1

Presentation to Te Awarua-o-Porirua Whaitua Committee 27.10.2018 Paula Hammond – Policy Advisor

Recap of sediment objectives

Sedimentation rate objectives

• The net average sedimentation rate is less than

2mm per year in the Pauatahanui Arm (assessed as the rolling average over the most recent five years of data).

• The net average sedimentation rate is less than

1mm per in the Onepoto Arm (assessed as the rolling average over the most recent five years of data).

Recap of sediment objectives

Muddiness objectives

• Sediment mud content does not exceed 20% in the intertidal

sediments and should not increase from current state.

• Spatial extent of soft mud shall not exceed 15% of the

available intertidal area and no increase in soft mud area from current state.

Sources of sediment

• Earthworks
• Forestry
• Erosion prone land – tomorrow’s workshop
• Stream bank erosion – tomorrow’s workshop

Earthworks

Current policy direction

• Permitted activity rules in PCC, WCC and GWRC plans
• Policies in PNRP aimed at managing sediment and erosion
• PCC - bylaw to prevent silt and sediment entering

stormwater

• WCC – guide for WSUD stormwater management that

includes Earthworks design and construction

• GWRC – small earthworks guidelines, erosion and sediment

control guidelines

Earthworks recommendations (s4 Pg 27)

• 1. Wellington City Council considers developing a Silt and Sediment control

bylaw similar to PCC’s

• 2. Greater Wellington reviews publications, including Small earthworks – Erosion

and sediment control for small sites, to ensure the methods and principles included are still relevant and applicable.

• 3. Greater Wellington, in conjunction with WCC and PCC, develop an education

and compliance programme to ensure good practice in relation to silt and sediment control is undertaken on small sites.

• 4. Greater Wellington considers whether to cap the amount of earthworks

(areas greater than 3000m2) that are ‘open’ at any one time within the Whaitua.

Forestry

Current policy direction

• National Environmental Standards for Plantation

Forestry

– Permits all forestry operations within whaitua, but

– Earthworks management plan required for works over 500m2 – Harvest plans must be prepared for all sites

– GWRC can request Earthworks and Harvest Plans and can charge for monitoring permitted activities

Erosion susceptibility classification

Level of risk

Low – Green Moderate – Yellow High – Orange Very high - Red

Forestry recommendations (s4 Pg 29)

• 1. Greater Wellington works with the forestry sector to identify barriers to good

practice in reducing sediment from forestry operations and discuss what would be most helpful to them to overcome these.

• 2. Upon receiving notice under the NPS-PF of earthworks, forestry quarrying or

harvesting in the Te Awarua-o-Porirua Whaitua, Greater Wellington requests a copy of the Forestry earthworks management plan and harvest plan or Quarry erosion and sediment management plan and actively monitors compliance to ensure sediment discharges to waterbodies are minimised.